    1. Field of the Invention
The present invention relates to an electrode for a lithium battery and a lithium battery using the electrode.    2. Description of the Related Art
Since a secondary lithium ion battery has a higher energy density and lighter weight compared to a conventional secondary battery, it has been widely used as a power source for portable electronic devices which is reduced in size and becomes increasingly sophisticated. Also, using a secondary lithium battery as power source for power tools and as a battery for electric vehicles has been studied in recent years.
With respect to a power source for power tools and a battery for electric vehicles, various efforts have been made to improve the large current characteristics, for example, to reduce the resistance in the electrode when a large current is passed therethrough.
Patent Document 1 discloses a negative electrode material in which a granulated graphitic material is coated by and integrated with a fibrous graphite material through the intermediary of a low crystallinity graphitic material. When focused on one negative electrode particle, the circumference of a granulated graphitic material is surrounded by a fibrous graphite material and a coating of another carbon material is formed thereon. This keeps the granulated graphitic material and the fibrous graphite material tightly adhered to each other. However, when the powder is taken as a whole, it is difficult to reduce the electrode resistance as expected. This is because contact between the negative electrode materials is due to contact between low crystallinity graphitic materials.
Patent Document 2 discloses an invention for reducing the internal resistance of a battery by mixing fine carbon fibers into the positive electrode material. This invention poses a problem in that the mixing of fine carbon fibers which generally have a lower bulk density than the positive electrode material reduces the packing density of the electrode. This results in a decrease in capacitance and degradation of the load characteristics of the battery.